1. Field of the Invention
The present invention relates to an optical pickup device which performs recording/reproducing processing to an optical disk and an optical disk device using the same, and particularly relates to an optical pickup device which has a flexible substrate having a short-circuit wiring portion and an optical disk device using the same.
2. Description of the Related Art
In recent years, optical disks become widespread and high performance is required for optical disk devices for performing recording/reproducing processing. In a conventional optical disk device, a high-frequency wave of about 350 MHz is superimposed on a semiconductor laser diode mounted on an integrated optical unit IOU in the optical pickup device from a driving circuit of the semiconductor laser diode formed on a flexible substrate, in order to improve signal characteristics during reproducing a DVD (Digital Versatile Disc).
However, in case of a long distance between the integrated optical unit on which the semiconductor laser diode is mounted and the driving circuit on the flexible substrate, because of superimposing the high-frequency, attenuation of a driving signal and generation of heat occur under the influence of line inductance in a wiring path detouring on the flexible substrate. This causes a serious problem in the case of writing processing, which requires laser driving current of about tenfold of energy compared with read of a ROM (Read Only Memory), and also a problem of degradation of writing characteristics.
That is, in the flexible substrate of the conventional optical pickup apparatus, when the high-frequency wave is superposed on the semiconductor laser diode in reproducing DVD and CD, in the case of the long wiring path between the semiconductor laser diode and the driving circuit on the flexible substrate, the attenuation of the driving signal and the generation of heat occur under the influence of line inductance. Also, an unnecessary electromagnetic wave is also generated, which results in the degradation of the writing characteristics into the optical disk.